CHANCE OF STORMS: NOAA forecasters estimate a 60% to 65% chance of polar geomagnetic storms on Nov. 23/24 when a pair of CMEs is expected to hit Earth's magnetic field. The incoming clouds were propelled toward Earth by the recent eruptions of sunspot AR1618. Black Friday might be tinged red and green by the glow of high-latitude auroras. SUNSPOT AR1618--UPDATE: Sunspot AR1618 has experienced some decay during the past 24 hours, but it is still potent. The sunspot's magnetic canopy has a 'beta-gamma-delta' configuration that harbors energy for X-class solar flares. Because of the sunspot's nearly central location on the solar disk, any eruptions today would be Earth-directed. A sunspot, like AR1618, is a vast island of magnetism floating on the surface of the sun. Magnetic fields bubble up from the sun's interior to form the sunspot's dark cores much like a Pacific island forming from the lava of an undersea volcano. Phil Scherrer, a member of the Solar Dynamics Observatory science team at Stanford University, has prepared an 8-day movie showing the genesis of AR1618: [go to www.spaceweather.com to watch movie]

A companion movie shows the region's magnetic development. In the movie, which Scherrer made using data from SDO's Helioseismic and Magnetic Imager (HMI), white denotes positive polarity, black denotes negative. Places with mixed polarities are where the magnetic fields can reconnect and erupt, producing solar flares. www.spaceweather.com